MicroRNA-29a suppresses cardiac fibroblasts proliferation via targeting VEGF-A/MAPK signal pathway

MicroRNAs regulating signaling pathways in cardiac fibrosis: potential role of the exercise training

Cardiovascular and metabolic diseases such as hypertension, type 2 diabetes, and obesity develop long-term fibrotic processes in the heart, promoting pathological cardiac remodeling, including after myocardial infarction, reparative fibrotic processes also occur. These processes are regulated by many intracellular signaling pathways that have not yet been completely elucidated, including those associated with microRNA (miRNA) expression. miRNAs are small RNA transcripts (18-25 nucleotides in length) that act as posttranscriptionally regulators of gene expression, inhibiting or degrading one or more target messenger RNAs (mRNAs), and proven to be involved in many biological processes such as cell cycle, differentiation, proliferation, migration, and apoptosis, directly affecting the pathophysiology of several diseases, including cardiac fibrosis. Exercise training can modulate the expression of miRNAs and it is known to be beneficial in various cardiovascular diseases, attenuating cardiac fibrosis processes. However, the signaling pathways modulated by the exercise associated with miRNAs in cardiac fibrosis were not fully understood. Thus, this review aims to analyze the expression of miRNAs that modulate signaling pathways in cardiac fibrosis processes that can be regulated by exercise training.

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

Axitinib targets cardiac fibrosis in pressure overload-induced heart failure through VEGFA-KDR pathway

Background

There are no specific clinical medications that target cardiac fibrosis in heart failure (HF). Recent studies have shown that tyrosine kinase inhibitors (TKIs) may benefit fibrosis in various organs. However, there is limited research on their application in cardiac fibrosis. Axitinib, an FDA-approved tyrosine kinase inhibitor, was used to evaluate its effects on cardiac fibrosis and function in pressure overload-induced heart failure.

Methods

To build a pharmacological network, the pharmacological targets of axitinib were first retrieved from databases and coupled with key heart failure gene molecules for analysis and prediction. To validate the results outlined above, 8-week-old male C57BL/6 J mice were orally administrated of axitinib (30 mg/kg) daily for 8 weeks after Transverse Aortic Constriction (TAC) surgery. Mouse cardiomyocytes and cardiac fibroblasts were used as cell lines to test the function and mechanism of axitinib.

Results

We found that the pharmacological targets of axitinib could form a pharmacological network with key genes involved in heart failure. The VEGFA-KDR pathway was found to be closely related to the differential gene expression of human heart-derived primary cardiomyocyte cell lines treated with axitinib, based on analysis of the publicly available dataset. The outcomes of animal experiments demonstrated that axitinib therapy greatly reduced cardiac fibrosis and improved TAC-induced cardiac dysfunction. Further research has shown that the expression of transforming growth factor-β(TGF-β) and other fibrosis genes was significantly reduced in vivo and in vitro.

Conclusion

Our study provides evidence for the repurposing of axitinib to combat cardiac fibrosis, and offers new insights into the treatment of patients with HF.

Downregulation of fibrosis related hsa-miR-29c-3p in human CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) represent structural and functional urinary system malformations and take place as one of the most common congenital malformations with an incidence of 1:500. Ureteral obstruction-induced hydronephrosis is associated with renal fibrosis and chronic kidney diseases in the pediatric CAKUT. We aimed to construct interaction network of previously bioinformatically associated miRNAs with CAKUT differentially expressed genes in order to prioritize those associated with fibrotic process and to experimentally validate the expression of selected miRNAs in CAKUT patients compared to control group. We constructed interaction network of hsa-miR-101-3p, hsa-miR-101-5p and hsa-miR-29c-3p that showed significant association with fibrosis. The top enriched molecular pathway was extracellular matrix-receptor interaction (adjusted p = .0000263). We experimentally confirmed expression of three miRNAs (hsa-miR-29c-3p, hsa-miR-101-3p and hsa-miR-101-5p) in obstructed ureters (ureteropelvic junction obstruction and primary obstructive megaureter) and vesicoureteral reflux. The hsa-miR-29c-3p was shown to have lower expression in both patient groups compared to controls. Relative levels of hsa-miR-101-5p and hsa-miR-101-3p showed significant positive correlations in both groups of patients. Statistically significant correlation was observed between hsa-miR-101 (-3p and -5p) and hsa-miR-29c-3p only in the obstructed group. The significant downregulation of anti-fibrotic hsa-miR-29c-3p in obstructive CAKUT could explain activation of genes involved in fibrotic processes. As miRNAs are promising candidates in therapeutic approaches our results need further measurement of fibrotic markers or assessment of extent of fibrosis and functional evaluation of hsa-miR-29c.

Suppression of NADPH oxidase 4 inhibits PM2.5-induced cardiac fibrosis through ROS-P38 MAPK pathway

Fine particulate matter (PM_2.5) has been consistently linked to cardiovascular diseases, and cardiac fibrosis plays a crucial role in the occurrence and development of heart diseases. It is reported that NOX4-dependent redox signaling are responsible for TGFβ-mediated profibrotic responses. The current study was designed to explore the possible mechanisms of cardiac fibrosis by PM_2.5 both in vitro and in vivo. Female C57BL/6 mice received PM_2.5 (3 mg/kg b.w.) exposure with/without NOX4 inhibitor (apocynin, 25 mg/kg b.w.) or ROS scavenger (NALC, 50 mg/kg b.w.), every other day, for 4 weeks. H9C2 cells were incubated with PM_2.5 (3 μg/mL) with/without 5 mM NALC, TGFβ inhibitor (SB431542, 10 μM), or siRNA-NOX4 for 24 h. The results demonstrated that PM_2.5 induced evident collagen deposition and elevated expression of fibrosis biomarkers (Col1a1 & Col3a1). Significant systemic inflammatory response and cardiac oxidative stress were triggered by PM_2.5. PM_2.5 increased the protein expression of TGFβ1, NOX4, and P38 MAPK. Notably, the increased effects of PM_2.5 could be suppressed by SB431542, siRNA-NOX4 in vitro or apocynin in vivo, and NALC. The reverse verification experiments further supported the involvement of the TGFβ/NOX4/ROS/P38 MAPK signaling pathway in the myocardial fibrosis induced by PM_2.5. In summary, the current study provided evidence that PM_2.5 challenge led to cardiac fibrosis through oxidative stress, systemic inflammation, and subsequent TGFβ/NOX4/ROS/P38 MAPK pathway and may offer new therapeutic targets in cardiac fibrosis.

New Insights into the Functions of MicroRNAs in Cardiac Fibrosis: From Mechanisms to Therapeutic Strategies

Cardiac fibrosis is a significant global health problem associated with almost all types of heart disease. Extensive cardiac fibrosis reduces tissue compliance and contributes to adverse outcomes, such as cardiomyocyte hypertrophy, cardiomyocyte apoptosis, and even heart failure. It is mainly associated with pathological myocardial remodeling, characterized by the excessive deposition of extracellular matrix (ECM) proteins in cardiac parenchymal tissues. In recent years, a growing body of evidence demonstrated that microRNAs (miRNAs) have a crucial role in the pathological development of cardiac fibrosis. More than sixty miRNAs have been associated with the progression of cardiac fibrosis. In this review, we summarized potential miRNAs and miRNAs-related regulatory mechanisms for cardiac fibrosis and discussed the potential clinical application of miRNAs in cardiac fibrosis.

Non-coding RNAs: Important participants in cardiac fibrosis

Cardiac remodeling is a pathophysiological process activated by diverse cardiac stress, which impairs cardiac function and leads to adverse clinical outcome. This remodeling partly attributes to cardiac fibrosis, which is a result of differentiation of cardiac fibroblasts to myofibroblasts and the production of excessive extracellular matrix within the myocardium. Non-coding RNAs mainly include microRNAs and long non-coding RNAs. These non-coding RNAs have been proved to have a profound impact on biological behaviors of various cardiac cell types and play a pivotal role in the development of cardiac fibrosis. This review aims to summarize the role of microRNAs and long non-coding RNAs in cardiac fibrosis associated with pressure overload, ischemia, diabetes mellitus, aging, atrial fibrillation and heart transplantation, meanwhile shed light on the diagnostic and therapeutic potential of non-coding RNAs for cardiac fibrosis.

Tripartite Motif 38 Attenuates Cardiac Fibrosis after Myocardial Infarction by Suppressing TAK1 Activation via TAB2/3 Degradation

The role of tripartite motif (TRIM) 38, a ubiquitin E3 ligase regulating various pathophysiological processes, in cardiac fibrosis remains unclear. Here, a model of angiotensin II and myocardial infarction (MI)-induced fibrosis was established to explore its role in cardiac fibrosis and its underlying mechanisms. Cardiac fibrosis in the mouse MI model was mitigated by TRIM38 overexpression, but aggravated by its depletion. Consistently, in vitro overexpression or knockdown of TRIM38 ameliorated or aggravated the proliferation and secretion of cardiac fibroblasts (CFs) exposed to fibrotic stimulation, respectively. Mechanistically, TRIM38 suppressed cardiac fibrosis progression by attenuating TAK1/MAPK signaling. Inhibiting TAK1/MAPK signaling with a pharmacological inhibitor greatly reversed the effects of TRIM38 knockdown on CF secretion. Specifically, TRIM38 interacted with and “targeted” TAB2 and TAB3 for degradation, subsequently inhibiting TAK1 phosphorylation and negatively regulating MAPK signaling. These findings can help develop therapeutic strategies to treat and prevent cardiac fibrosis.

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TRIM38 expression is negatively correlated with cardiac fibrosis progression

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TRIM38 ameliorates the proliferation and secretion of CFs post fibrotic stimulation

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TRIM38 overexpression attenuates cardiac fibrosis progression in MI mice

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TRIM38 inhibits the TAK1/MAPK pathway by targeting the degradation of TAB2 and TAB3

MicroRNA-451a attenuates angiotensin II-induced cardiac fibrosis and inflammation by directly targeting T-box1

Hypertension or angiotensin II (Ang II) induces cardiac inflammation and fibrosis, thus contributing to cardiac remodeling. MicroRNAs (miRNAs) are considered crucial regulators of cardiac homeostasis and remodeling in response to various types of stress. It has been reported that miR-451a is involved in regulating ischemic heart injury. However, its role in Ang II-induced cardiac fibrosis remains unknown. Cardiac remodeling was induced in mice by infusion of low-dose Ang II (490 ng/kg/min) with a minipump for 2 weeks. Echocardiography and histological examinations were performed to evaluate cardiac function and pathological changes. We observed that miR-451a expression was the most significantly downregulated in the hearts of Ang II-infused mice and in both primary cardiac myocytes and fibroblasts. Overexpression of miR-451a in mice significantly attenuated Ang II-induced cardiac fibrosis and inflammation. Conversely, knockdown of miR-451a in mice aggravated this effect. Bioinformatics analysis and a luciferase reporter assay revealed that TBX1 was a direct target of miR-451a. Mechanistically, miR-451a directly targeted TBX1 expression, which inhibited TGF-β1 production in both cardiac myocytes and fibroblasts, inactivating of TGF-β1/SMAD2/3 signaling, inhibiting myofibroblast differentiation and proinflammatory cytokine expression, and leading to attenuation of cardiac fibrosis and inflammation. In conclusion, these results indicate that miR-451a acts as a novel regulator of Ang II-induced cardiac fibrosis and inflammation by directly targeting TBX1, and may be a promising therapeutic target for treating hypertensive cardiac diseases.

Role of the microRNA-29 family in myocardial fibrosis

Myocardial fibrosis (MF) is an inevitable pathological process in the terminal stage of many cardiovascular diseases, often leading to serious cardiac dysfunction and even death. Currently, microRNA-29 (miR-29) is thought to be a novel diagnostic and therapeutic target of MF. Understanding the underlying mechanisms of miR-29 that regulate MF will provide a new direction for MF therapy. In the present review, we concentrate on the underlying signaling pathway of miR-29 affecting MF and the crosstalk regulatory relationship among these pathways to illustrate the complex regulatory network of miR-29 in MF. Additionally, based on our mechanistic understanding, we summarize opportunities and challenges of miR-29-based MF diagnosis and therapy.

miR-15a-5p suppresses peritoneal fibrosis induced by peritoneal dialysis via targeting VEGF in rats

Aim

When peritoneal fibrosis (PF) causes ultrafiltration failure in peritoneal dialysis (PD) patients, PD has to be discontinued. Currently, there is no effective way to relieve PF. In this study, we aimed to determine whether miR-15a-5p is involved in PF and to determine the underlying mechanism.

Methods

Six normal rats were used as the control group. A uremic rat model was constructed using 5/6 nephrectomy in a Sprague–Dawley model. The uremic rats were randomly divided into PD, lentivirus-transfected, negative control, VEGFR-inhibited and gavage control groups. Except for the control group, all uremia rats received continuous PD for 28 days. In the lentivirus-transfected group, the miR-15a-5p plasmid was injected into the peritoneal cavity to upregulate miR-15a-5p expression. Axitinib was used to block vascular endothelial growth factor receptor (VEGFR) in the peritoneum. The mRNA levels of miR-15a-5p and VEGF were detected by qRT-PCR and FISH. Protein levels of VEGF, E-cadherin, collagen IV, fibronectin and α-SMA were detected by western blot and immunohistochemistry.

Results

PD leads to peritoneal thickening and fibrosis. The expression level of miR-15a-5p decreased and that of VEGF increased in the PD group than in the controls. Additionally, E-cadherin was significantly reduced while collagen IV, fibronectin and α-SMA were obviously increased in the PD group compared to controls. FISH showed that VEGF might be the target gene of miR-15a-5p. Overexpression of miR-15a-5p or inhibition of VEGFR could reverse PF.

Conclusion

miR-15a-5p may participate in the endothelial to mesenchymal transition of PF caused by PD through VEGF.

Epigenetics-based therapeutics for myocardial fibrosis

Myocardial fibrosis (MF) is a reactive remodeling process in response to myocardial injury. It is mainly manifested by the proliferation of cardiac muscle fibroblasts and secreting extracellular matrix (ECM) proteins to replace damaged tissue. However, the excessive production and deposition of extracellular matrix, and the rising proportion of type I and type III collagen lead to pathological fibrotic remodeling, thereby facilitating the development of cardiac dysfunction and eventually causing heart failure with heightened mortality. Currently, the molecular mechanisms of MF are still not fully understood. With the development of epigenetics, it is found that epigenetics controls the transcription of pro-fibrotic genes in MF by DNA methylation, histone modification and noncoding RNAs. In this review, we summarize and discuss the research progress of the mechanisms underlying MF from the perspective of epigenetics, including the newest m6A modification and crosstalk between different epigenetics in MF. We also offer a succinct overview of promising molecules targeting epigenetic regulators, which may provide novel therapeutic strategies against MF.

MiR-503 suppresses fibroblast activation and myofibroblast differentiation by targeting VEGFA and FGFR1 in silica-induced pulmonary fibrosis

Inhalation and deposition of crystalline silica particles in the lung can cause pulmonary fibrosis, then leading to silicosis. Given the paucity of effective drugs for silicosis, new insights for understanding the mechanisms of silicosis, including lung fibroblast activation and myofibroblast differentiation, are essential to explore therapeutic strategies. Our previous research showed that the up-regulation of miR-503 alleviated silica-induced pulmonary fibrosis in mice. In this study, we investigated whether miR-503 can regulate the TGF-β1-induced effects in lung fibroblasts. Mimic-based strategies aiming at up-regulating miR-503 were used to discuss the function of miR-503 in vivo and in vitro. We found that the expression level of miR-503 was decreased in fibroblasts stimulated by TGF-β1, and the up-regulation of miR-503 reduced the release of fibrotic factors and inhibited the migration and invasion abilities of fibroblasts. Combined with the up-regulation of miR-503 in a mouse model of silica-induced pulmonary fibrosis, we revealed that miR-503 mitigated the TGF-β1-induced effects in fibroblasts by regulating VEGFA and FGFR1 and then affecting the MAPK/ERK signalling pathway. In conclusion, miR-503 exerted protective roles in silica-induced pulmonary fibrosis and may represent a novel and potent candidate for therapeutic strategies in silicosis.

Uncovering potential differentially expressed miRNAs and targeted mRNAs in myocardial infarction based on integrating analysis

Myocardial infarction (MI) is one of the leading causes of death globally. The aim of the present study was to find valuable microRNAs (miRNAs/miRs) and target mRNAs in order to contribute to our understanding of the pathology of MI. miRNA and mRNA data were downloaded for differential expression analysis. Then, a regulatory network between miRNAs and mRNAs was established, followed by function annotation of target mRNAs. Thirdly, prognosis and diagnostic analysis of differentially methylated target mRNAs were performed. Finally, an in vitro experiment was used to validate the expression of selected miRNAs and target mRNAs. A total of 19 differentially expressed miRNAs and 1,007 differentially expressed mRNAs were identified. Several regulatory interaction pairs between miRNA and mRNAs were identified, such as hsa-miR-142-2p-long-chain-fatty-acid-CoA ligase 1 (ACSL1), hsa-miR-15a-3p-nicotinamide phosphoribosyltransferase (NAMPT), hsa-miR-33b-5p-regulator of G-protein signaling 2 (RGS2), hsa-miR-17-3p-Jun dimerization protein 2 (JDP2), hsa-miR-24-1-5p-aquaporin-9 (AQP9) and hsa-miR-34a-5p-STAT1/AKT3. Of note, it was demonstrated that ACSL1, NAMPT, RGS2, JDP2, AQP9, STAT1 and AKT3 had diagnostic and prognostic values for patients with MI. In addition, STAT1 was involved in the ‘chemokine signaling pathway’ and ‘Jak-STAT signaling pathway’. AKT3 was involved in both the ‘MAPK signaling pathway’ and ‘T cell receptor signaling pathway’. Reverse transcription-quantitative PCR validation of hsa-miR-142-3p, hsa-miR-15a-3p, hsa-miR-33b-5p, ACSL1, NAMPT, RGS2 and JDP2 expression was consistent with the bioinformatics analysis. In conclusion, the identified miRNAs and mRNAs may be involved in the pathology of MI.

Function analysis of differentially expressed microRNAs in TGF-β1-induced cardiac fibroblasts differentiation

BACKGROUND

Cardiac fibroblasts differentiation plays a critical role in cardiac remodeling and failure, but the underlying molecular mechanisms are still poorly understood. MicroRNAs (miRNAs) had been identified as important regulators during cell differentiation. The aim of the present study was to screen the miRNAs involved in regulation of cardiac fibroblasts differentiation.

METHODS

The differentiation of rat cardiac fibroblasts into myofibroblasts was induced by transforming growth factor-β1 (TGF-β1). Small RNA sequencing was then applied to detect the differentially expressed miRNAs.

RESULTS

A total of 450 known miRNAs were detected, and 127 putative novel miRNAs were predicted by miRDeep2 analysis. DEGseq analysis and qRT-PCR confirmed that 24 known miRNAs were differentially expressed in TGF-β1-induced cardiac fibroblasts, including three up-regulated miRNAs and 21 down-regulated miRNAs. After miRNAs target genes prediction by miRanda algorithm, pathway analysis showed that these potential target genes were involved in Calcium signaling pathway, Type II diabetes mellitus, and Glutamatergic synapse pathway, etc. Meanwhile, seven putative miRNAs were also detected differentially expressed during TGF-β1-induced cardiac fibroblasts differentiation.

CONCLUSIONS

These differentially expressed miRNAs might play critical roles in cardiac fibroblasts differentiation. Altered expression of miRNAs may yield new insights into the underlying mechanisms of cardiac fibrosis and provide novel mechanism-based therapeutic strategies for cardiac fibrosis.

FOXF1 ameliorates angiotensin II-induced cardiac fibrosis in cardiac fibroblasts through inhibiting the TGF-β1/Smad3 signaling pathway

Cardiac fibrosis is a pathological feature common to a variety of heart diseases such as myocardial infarction, arrhythmias, cardiomyopathies and heart failure. The molecular mechanism underlying the cardiac fibrosis is still unclear. Forkhead box F1 (FOXF1), a member of the forkhead transcription factor superfamily, plays critical roles in the development of hepatic fibrosis. However, whether FOXF1 is involved in the pathogenesis of cardiac fibrosis remains to be elucidated. The present study aimed to investigate the role of FOXF1 and its mechanisms in regulating cardiac fibrosis. The results demonstrated that FOXF1 was downregulated in Ang II-induced CFs. Overexpression of FOXF1 inhibited angiotensin II (Ang II)-induced proliferation, migration and oxidative stress in cardiac fibroblasts (CFs). Overexpression of FOXF1 also reduced the expression of alpha-smooth muscle actin (a-SMA) in Ang II-induced CFs, suggesting that overexpression of FOXF1 prevented the differentiation of CFs to myofibroblasts. Furthermore, the production of extracellular matrix (ECM) components including type I collagen and fibronectin were reduced by overexpression of FOXF1 in Ang II-induced CFs. Furthermore, overexpression of FOXF1 prevented Ang II-induced activation of transforming growth factor beta 1 (TGF-β1)/Smad3 pathway in CFs. In conclusion, the results of the present study indicated that FOXF1 acted as a key regulator of pathological cardiac fibrosis, and overexpression of FOXF1 ameliorated cardiac fibrosis by inhabiting the TGF-β1/Smad3 signaling pathway. These results indicated that FOXF1 may be a novel target for attenuating cardiac fibrosis.

miR-29a Promotes the Neurite Outgrowth of Rat Neural Stem Cells by Targeting Extracellular Matrix to Repair Brain Injury

Neural stem cells (NSCs) can generate new neurons to repair brain injury and central nervous system disease by promoting neural regeneration. MicroRNAs (miRNAs) involve in neural development, brain damage, and neurological diseases repair. Recent reports show that several miRNAs express in NSCs and are important to neurogenesis. Neurites play a key role in NSC-related neurogenesis. However, the mechanism of NSC neurite generation is rarely studied. We surprisingly noticed that the neurites increased after bone morphogenetic protein (BMP) treatment in rat NSCs. This process was accompanied by the dynamic change of miRNA-29. Then we discovered that miR-29a regulated neural neurites in rat hippocampus NSCs. Overexpression of miR-29a reduced the cell soma area and promoted the neurite outgrowth of NSCs. Cell soma area became small, whereas the number of neurite increased. Moreover, neurite complexity increased dramatically, with more primary and secondary branches after miR-29a overexpression. In addition, miR-29a overexpression still maintained the stemness of NSCs. Besides, we identified that miR-29a can promote the neurite outgrowth by targeting extracellular matrix-related genes like Fibrillin 1 (Fbn1), Follistatin-like 1 (Fstl1), and laminin subunit gamma 2 (Lamc2). These findings may provide a novel role of miR-29a to regulate neurite outgrowth and development of NSCs. We also offered a possible theoretical basis to the migration mechanism of NSCs in brain development and damage repair.

Gracillin inhibits apoptosis and inflammation induced by lipopolysaccharide (LPS) to alleviate cardiac injury in mice via improving miR-29a

Sepsis induces critical myocardial dysfunction, resulting in an increased mortality. Gracillin (GRA) is a natural steroidal saponin, showing strong capacities of anti-inflammation, but its pharmacological effects on lipopolysaccharide (LPS)-induced acute cardiac injury still remain unclear. In this study, we attempted to explore if GRA was effective to attenuate cardiac injury in LPS-challenged mice and the underlying mechanisms. First, we found that GRA treatments markedly up-regulated the expression of miR-29a in cardiomyocytes. LPS-induced cytotoxicity in cardiomyocytes was significantly alleviated by GRA treatment, as evidenced by the improved cell viability and reduced lactate dehydrogenase (LDH) release. In addition, LPS-triggered apoptotic cell death was clearly ameliorated in cardiomyocytes co-treated with GRA. Notably, LPS-exposed cells showed significantly reduced expression of miR-29a, while being rescued by GRA treatment. In vivo, LPS apparently impaired cardiac function in mice, which was, however, alleviated by GRA administration. In addition, GRA markedly attenuated apoptosis in hearts of LPS-challenged mice by decreasing the expression of cleaved Caspase-3. LPS-triggered inflammatory response in cardiac tissues was also suppressed by GRA through blocking nuclear factor κB (NF-κB) signaling pathway. We also found that miR-29a expression was highly reduced in hearts of LPS-treated mice but was rescued by GRA pretreatment. Besides, miR-29a mimic alleviated LPS-induced apoptosis and inflammation in cardiomyocytes; however, LPS-caused effects were further accelerated by miR-29a. Of note, the protective effects of GRA on LPS-injured cardiac tissues were significantly abrogated by miR-29a suppression. In conclusion, our findings demonstrated that GRA exerted an effective role against LPS-induced acute cardiac injury through impeding apoptosis and inflammation regulated by miR-29a.

The diagnostic value of circulating microRNAs in heart failure

Heart failure (HF) is a complex clinical syndrome, characterized by inadequate blood perfusion of tissues and organs caused by decreased heart ejection capacity resulting from structural or functional cardiac disorders. HF is the most severe heart condition and it severely compromises human health; thus, its early diagnosis and effective management are crucial. However, given the lack of satisfactory sensitivity and specificity of the currently available biomarkers, the majority of patients with HF are not diagnosed early and do not receive timely treatment. A number of studies have demonstrated that peripheral blood circulating nucleic acids [such as microRNAs (miRs), mRNA and DNA] are important for the diagnosis and monitoring of treatment response in HF. miRs have been attracting increasing attention as promising biomarkers, given their presence in body fluids and relative structural stability under diverse conditions of sampling. The aim of the present review was to analyze the associations between the mechanisms underlying the development of HF and the expression of miRs, and discuss the value of using circulating miRs as diagnostic biomarkers in HF management. In particular, miR-155, miR-22 and miR-133 appear to be promising for the diagnosis, prognosis and management of HF patients.

Developing a panel of biomarkers and miRNA in patients with myocardial infarction for early intervention strategies of heart failure in West Virginian population

Background

Myocardial infarction is the most common cause of heart failure. MI has been intricately linked to ventricular remodeling, subsequently leading to the reduction in the cardiac ejection fraction causing HF. The cumulative line of evidence suggests an important role of several biomarkers in modulating the cardiac vasculature, further contributing towards the progression of post-MI complications. Studies have demonstrated, yet not fully established, that an important biomarker, IL-10, has a causal relationship with MI and associated cardiac dysfunction.

Hypothesis

This study aims to establish the role of IL-10 as a prognostic marker for the cardiovascular outcomes and to develop a panel of biomarkers and circulating miRNAs that could potentially result in the early detection of HF resulting from MI, allowing for early intervention strategies.

Methods and results

Blood was withdrawn and echocardiography assessment was performed on a total of 43 patients that were enrolled, within 24 hours of the incidence of MI. Patients were divided in three main groups, based on the ejection fraction measurement from echocardiography: control (n = 14), MI with normal EF (MI+NEF, n = 13) and MI with low EF (MI+LEF, n = 16). Our results showed that TGFβ-1, TNF-α, IL-6 and MMP-9 were upregulated significantly in MI+NEF group and more so in MI+LEF group, as compared to control group (p<0.01). The circulating levels of miR-34a, miR-208b and miR-126 were positively correlated and showed elevated levels in the MI+NEF group, even higher in MI+LEF group, while levels of miR-24 and miR-29a were reduced in MI+NEF, and much lower in MI+LEF, as compared to the control group (p<0.01). Our results also demonstrated a direct correlation of IL-10 with the ejection fraction in patients with MI: IL-10 was elevated in MI+NEF group, however, the levels were significantly low in MI+LEF group suggesting an important role of IL-10 in predicting heart failure. Importantly, our study confirmed the correlation of IL-10 with EF by our follow-up echocardiography assessment that was performed 2 months after the incidence of MI.

Conclusion

Our results support the clinical application of these serum biomarkers to develop a panel for appropriate prognosis and management of adverse cardiac remodeling and development of heart failure post-myocardial infarction.

Inhibitory effect and molecular mechanism of mesenchymal stem cells on NSCLC cells

Non-small-cell lung cancer (NSCLC) is still the main threat of cancer-associated death. Current treatment of NSCLC has limited effectiveness, and unfortunately, the prognosis of NSCLC remains poor. Therefore, a novel strategy for cancer therapy is urgently needed. Stem cell therapy has significant potential for cancer treatment. Mesenchymal stem cells (MSCs) with capacity for self-renewal and differentiation into various cells types exhibit the feature of homing to tumor site and immunosuppression, have been explored as a new treatment for various cancers. Studies revealed that the broad repertoire of trophic factors secreted by MSCs extensively involved in the interplay between MSCs and tumor cells. In this study, we confirmed that MSCs do have the paracrine effect on proliferation and migration of NSCLC cells (A549, NCI-H460, and SK-MES-1). Co-culture system and conditioned medium experiments results showed that soluble factors secreted by MSCs inhibited the proliferation of NSCLC cells in vitro. The scratch assay showed that conditioned medium of MSCs could suppress the migration of NSCLC cells in vitro. Western blot results showed that the expression of proteins relevant to cell proliferation, anti-apoptosis, and migration was remarkably decreased via MAPK/eIF4E signaling pathway. We speculated that soluble factors secreted by MSCs might be responsible for inhibitory mechanism of NSCLC cells. By Human Gene Expression Microarray Assay and recombinant Vascular Endothelial Growth Factor 165 (VEGF165) neutralizing experiment, we verified that VEGF might be responsible for the down-regulation of proteins related to cell proliferation, anti-apoptosis, and migration by suppressing translation initiation factor eIF4E via MAPK signaling pathway. Taken together, our study demonstrated that a possible trophic factor secreted by MSCs could manipulate translation initiation of NSCLC cells via MAPK signaling pathway, and significantly affect the fate of tumor cells, which will be a new strategy for cancer therapy.

MiRNA Deregulation in Cardiac Aging and Associated Disorders

The prevalence of age-related diseases is increasing dramatically, among which cardiac disease represents the leading cause of death. Aging of the heart is characterized by various molecular and cellular hallmarks impairing both cardiomyocytes and noncardiomyocytes, and resulting in functional deteriorations of the cardiac system. The aging process includes desensitization of β-adrenergic receptor (βAR)-signaling and decreased calcium handling, altered growth signaling and cardiac hypertrophy, mitochondrial dysfunction and impaired autophagy, increased programmed cell death, low-grade inflammation of noncanonical inflammatory cells, and increased ECM deposition. MiRNAs play a fundamental role in regulating the processes underlying these detrimental changes in the cardiac system, indicating that MiRNAs are crucially involved in aging. Among others, MiR-34, MiR-146a, and members of the MiR-17-92 cluster, are deregulated during senescence and drive cardiac aging processes. It is therefore suggested that MiRNAs form possible therapeutic targets to stabilize the aged failing myocardium.

MicroRNA-98 inhibits TGF-β1-induced differentiation and collagen production of cardiac fibroblasts by targeting TGFBR1

To investigate the effects of miR-98 on TGF-β1-induced cardiac fibrosis in human cardiac fibroblasts (HCFs), and to establish the mechanism underlying these effects, HCFs were transfected with miR-98 inhibitor or mimic, and then treated with or without TGF-β1. The level of miR-98 was determined by qRT-PCR in TGF-β1-induced HCFs. Cell differentiation and collagen accumulation of HCFs were detected by qRT-PCR and Western blot assays, respectively. The mRNA and protein expressions of TGFBR1 were determined by qRT-PCR and Western blotting. In this study, the outcomes showed that TGF-β1 could dramatically decrease the level of miR-98 in a time- and concentration-dependent manner. Upregulation of miR-98 dramatically improved TGF-β1-induced increases in cell differentiation and collagen accumulation of HCFs. Moreover, bioinformatics analysis predicted that the TGFBR1 was a potential target gene of miR-98. Luciferase reporter assay demonstrated that miR-98 could directly target TGFBR1. Inhibition of TGFBR1 had the similar effect as miR-98 overexpression. Downregulation of TGFBR1 in HCFs transfected with miR-98 inhibitor partially reversed the protective effect of miR-98 overexpression on TGF-β1-induced cardiac fibrosis in HCFs. Upregulation of miR-98 ameliorates TGF-β1-induced differentiation and collagen accumulation of HCFs by downregulation of TGFBR1. These results provide further evidence for protective effect of miR-98 overexpression on TGF-β1-induced cardiac fibrosis.

MicroRNA-9 inhibits high glucose-induced proliferation, differentiation and collagen accumulation of cardiac fibroblasts by down-regulation of TGFBR2

To investigate the effects of miR-9 on high glucose (HG)-induced cardiac fibrosis in human cardiac fibroblasts (HCFs), and to establish the mechanism underlying these effects. HCFs were transfected with miR-9 inhibitor or mimic, and then treated with normal or HG. Cell viability and proliferation were detected by using the Cell Counting Kit-8 (CCK-8) assay and Brdu-ELISA assay. Cell differentiation and collagen accumulation of HCFs were detected by qRT-PCR and Western blot assays respectively. The mRNA and protein expressions of transforming growth factor-β receptor type II (TGFBR2) were determined by qRT-PCR and Western blotting. Up-regulation of miR-9 dramatically improved HG-induced increases in cell proliferation, differentiation and collagen accumulation of HCFs. Moreover, bioinformatics analysis predicted that the TGFBR2 was a potential target gene of miR-9 Luciferase reporter assay demonstrated that miR-9 could directly target TGFBR2. Inhibition of TGFBR2 had the similar effect as miR-9 overexpression. Down-regulation of TGFBR2 in HCFs transfected with miR-9 inhibitor partially reversed the protective effect of miR-9 overexpression on HG-induced cardiac fibrosis in HCFs. Up-regulation of miR-9 ameliorates HG-induced proliferation, differentiation and collagen accumulation of HCFs by down-regulation of TGFBR2. These results provide further evidence for protective effect of miR-9 overexpression on HG-induced cardiac fibrosis.

Differential microRNA Expression and Regulation in the Rat Model of Post-Infarction Heart Failure

Background

Heart failure is a complex end stage of various cardiovascular diseases with a poor prognosis, and the mechanisms for development and progression of heart failure have always been a hot point. However, the molecular mechanisms underlying the post transcriptional regulation of heart failure have not been fully elucidated. Current data suggest that microRNAs (miRNAs) are involved in the pathogenesis of heart failure and could serve as a new biomarker, but the precise regulatory mechanisms are still unclear.

Methods

The differential miRNA profile in a rat model of post-infarction heart failure was determined using high throughout sequencing and analyzed through bioinformatics approaches. The results were validated using qRT-PCR for 8 selected miRNAs. Then the expression patterns of 4 miRNAs were analyzed in different periods after myocardial infarction. Finally, gain- and loss-of-function experiments of rno-miR-122-5p and rno-miR-184 were analyzed in H₂O₂ treated H9c2 cells.

Results

In the heart failure sample, 78 miRNAs were significantly upregulated and 28 were downregulated compared to the controls. GO and KEGG pathway analysis further indicated the likely roles of these miRNAs in heart failure. Time-course analysis revealed different expression patterns of 4 miRNAs: rno-miR-122-5p, rno-miR-199a-5p, rno-miR-184 and rno-miR-208a-3p. Additionally, rno-miR-122-5p and rno-miR-184 were proved to promote apoptosis in vitro.

Conclusions

Differential profile and expression patterns of miRNAs in the rats model of post-infarction heart failure were found, and the pro-apoptotic roles of rno-miR-122-5p and rno-miR-184 were revealed. These findings may provide a novel way that may assist in heart failure diagnosis and treatment.